Robot off-line programming system is known to the public for performing robot path generation. When off-line programming a robot for path generation, generally several factors are considered, such as tool settings, form of the to-be-machined work pieces, and robot positions, and so on. Based on the actual settings of these factors, machining targets can be determined to ensure the tool grasped by the robot could process an accurate machining while following the robot path. The more targets on the robot path could be machined, the better the machining effect achieves. After the basic settings like machining surface parameters and tool settings are set, the system generates a robot path with several targets. Each target has a defined coordinate. When the robot requires to process on a specific target, the robot follows a certain strategy, together with the coordinate information of the target, to adjust its orientation, which ensures the target can be machined.
However, even when a robot off-line programming is done to satisfy the conditions as mentioned above, it is not rare that problems occur such that some of the targets cannot be reached by the robot to process assuming certain postures, due to limited working range This will affect the machining effects and accuracy, and as a result, unexpected time and cost is required to build the robot system.